Expand description
The 8-bit unsigned integer type.
Implementations
Converts a string slice in a given base to an integer.
The string is expected to be an optional +
sign
followed by digits.
Leading and trailing whitespace represent an error.
Digits are a subset of these characters, depending on radix
:
0-9
a-z
A-Z
Panics
This function panics if radix
is not in the range from 2 to 36.
Examples
Basic usage:
assert_eq!(u8::from_str_radix("A", 16), Ok(10));
RunUnchecked integer addition. Computes self + rhs
, assuming overflow
cannot occur.
Safety
This results in undefined behavior when
self + rhs > u8::MAX
or self + rhs < u8::MIN
,
i.e. when checked_add
would return None
.
Unchecked integer subtraction. Computes self - rhs
, assuming overflow
cannot occur.
Safety
This results in undefined behavior when
self - rhs > u8::MAX
or self - rhs < u8::MIN
,
i.e. when checked_sub
would return None
.
Unchecked integer multiplication. Computes self * rhs
, assuming overflow
cannot occur.
Safety
This results in undefined behavior when
self * rhs > u8::MAX
or self * rhs < u8::MIN
,
i.e. when checked_mul
would return None
.
Returns the logarithm of the number with respect to an arbitrary base, rounded down.
This method might not be optimized owing to implementation details;
log2
can produce results more efficiently for base 2, and log10
can produce results more efficiently for base 10.
Panics
When the number is negative, zero, or if the base is not at least 2; it panics in debug mode and the return value is 0 in release mode.
Examples
#![feature(int_log)]
assert_eq!(5u8.log(5), 1);
RunReturns the logarithm of the number with respect to an arbitrary base, rounded down.
Returns None
if the number is zero, or if the base is not at least 2.
This method might not be optimized owing to implementation details;
checked_log2
can produce results more efficiently for base 2, and
checked_log10
can produce results more efficiently for base 10.
Examples
#![feature(int_log)]
assert_eq!(5u8.checked_log(5), Some(1));
RunUnchecked shift left. Computes self << rhs
, assuming that
rhs
is less than the number of bits in self
.
Safety
This results in undefined behavior if rhs
is larger than
or equal to the number of bits in self
,
i.e. when checked_shl
would return None
.
Unchecked shift right. Computes self >> rhs
, assuming that
rhs
is less than the number of bits in self
.
Safety
This results in undefined behavior if rhs
is larger than
or equal to the number of bits in self
,
i.e. when checked_shr
would return None
.
Wrapping (modular) multiplication. Computes self * rhs
, wrapping around at the boundary of the type.
Examples
Basic usage:
Please note that this example is shared between integer types.
Which explains why u8
is used here.
assert_eq!(10u8.wrapping_mul(12), 120);
assert_eq!(25u8.wrapping_mul(12), 44);
RunWrapping (modular) division. Computes self / rhs
.
Wrapped division on unsigned types is just normal division.
There’s no way wrapping could ever happen.
This function exists, so that all operations
are accounted for in the wrapping operations.
Examples
Basic usage:
assert_eq!(100u8.wrapping_div(10), 10);
RunWrapping Euclidean division. Computes self.div_euclid(rhs)
.
Wrapped division on unsigned types is just normal division.
There’s no way wrapping could ever happen.
This function exists, so that all operations
are accounted for in the wrapping operations.
Since, for the positive integers, all common
definitions of division are equal, this
is exactly equal to self.wrapping_div(rhs)
.
Examples
Basic usage:
assert_eq!(100u8.wrapping_div_euclid(10), 10);
RunWrapping (modular) remainder. Computes self % rhs
.
Wrapped remainder calculation on unsigned types is
just the regular remainder calculation.
There’s no way wrapping could ever happen.
This function exists, so that all operations
are accounted for in the wrapping operations.
Examples
Basic usage:
assert_eq!(100u8.wrapping_rem(10), 0);
RunWrapping Euclidean modulo. Computes self.rem_euclid(rhs)
.
Wrapped modulo calculation on unsigned types is
just the regular remainder calculation.
There’s no way wrapping could ever happen.
This function exists, so that all operations
are accounted for in the wrapping operations.
Since, for the positive integers, all common
definitions of division are equal, this
is exactly equal to self.wrapping_rem(rhs)
.
Examples
Basic usage:
assert_eq!(100u8.wrapping_rem_euclid(10), 0);
RunWrapping (modular) negation. Computes -self
,
wrapping around at the boundary of the type.
Since unsigned types do not have negative equivalents
all applications of this function will wrap (except for -0
).
For values smaller than the corresponding signed type’s maximum
the result is the same as casting the corresponding signed value.
Any larger values are equivalent to MAX + 1 - (val - MAX - 1)
where
MAX
is the corresponding signed type’s maximum.
Examples
Basic usage:
Please note that this example is shared between integer types.
Which explains why i8
is used here.
assert_eq!(100i8.wrapping_neg(), -100);
assert_eq!((-128i8).wrapping_neg(), -128);
RunPanic-free bitwise shift-left; yields self << mask(rhs)
,
where mask
removes any high-order bits of rhs
that
would cause the shift to exceed the bitwidth of the type.
Note that this is not the same as a rotate-left; the
RHS of a wrapping shift-left is restricted to the range
of the type, rather than the bits shifted out of the LHS
being returned to the other end. The primitive integer
types all implement a rotate_left
function,
which may be what you want instead.
Examples
Basic usage:
assert_eq!(1u8.wrapping_shl(7), 128);
assert_eq!(1u8.wrapping_shl(128), 1);
RunPanic-free bitwise shift-right; yields self >> mask(rhs)
,
where mask
removes any high-order bits of rhs
that
would cause the shift to exceed the bitwidth of the type.
Note that this is not the same as a rotate-right; the
RHS of a wrapping shift-right is restricted to the range
of the type, rather than the bits shifted out of the LHS
being returned to the other end. The primitive integer
types all implement a rotate_right
function,
which may be what you want instead.
Examples
Basic usage:
assert_eq!(128u8.wrapping_shr(7), 1);
assert_eq!(128u8.wrapping_shr(128), 128);
RunCalculates self
+ rhs
Returns a tuple of the addition along with a boolean indicating whether an arithmetic overflow would occur. If an overflow would have occurred then the wrapped value is returned.
Examples
Basic usage
assert_eq!(5u8.overflowing_add(2), (7, false));
assert_eq!(u8::MAX.overflowing_add(1), (0, true));
RunCalculates self + rhs + carry
without the ability to overflow.
Performs “ternary addition” which takes in an extra bit to add, and may return an additional bit of overflow. This allows for chaining together multiple additions to create “big integers” which represent larger values.
This can be thought of as a 8-bit “full adder”, in the electronics sense.
Examples
Basic usage
#![feature(bigint_helper_methods)]
assert_eq!(5u8.carrying_add(2, false), (7, false));
assert_eq!(5u8.carrying_add(2, true), (8, false));
assert_eq!(u8::MAX.carrying_add(1, false), (0, true));
assert_eq!(u8::MAX.carrying_add(0, true), (0, true));
assert_eq!(u8::MAX.carrying_add(1, true), (1, true));
assert_eq!(u8::MAX.carrying_add(u8::MAX, true), (u8::MAX, true));
RunIf carry
is false, this method is equivalent to overflowing_add
:
#![feature(bigint_helper_methods)]
assert_eq!(5_u8.carrying_add(2, false), 5_u8.overflowing_add(2));
assert_eq!(u8::MAX.carrying_add(1, false), u8::MAX.overflowing_add(1));
RunCalculates self
+ rhs
with a signed rhs
Returns a tuple of the addition along with a boolean indicating whether an arithmetic overflow would occur. If an overflow would have occurred then the wrapped value is returned.
Examples
Basic usage:
assert_eq!(1u8.overflowing_add_signed(2), (3, false));
assert_eq!(1u8.overflowing_add_signed(-2), (u8::MAX, true));
assert_eq!((u8::MAX - 2).overflowing_add_signed(4), (1, true));
RunCalculates self
- rhs
Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow would occur. If an overflow would have occurred then the wrapped value is returned.
Examples
Basic usage
assert_eq!(5u8.overflowing_sub(2), (3, false));
assert_eq!(0u8.overflowing_sub(1), (u8::MAX, true));
RunCalculates self - rhs - borrow
without the ability to overflow.
Performs “ternary subtraction” which takes in an extra bit to subtract, and may return an additional bit of overflow. This allows for chaining together multiple subtractions to create “big integers” which represent larger values.
Examples
Basic usage
#![feature(bigint_helper_methods)]
assert_eq!(5u8.borrowing_sub(2, false), (3, false));
assert_eq!(5u8.borrowing_sub(2, true), (2, false));
assert_eq!(0u8.borrowing_sub(1, false), (u8::MAX, true));
assert_eq!(0u8.borrowing_sub(1, true), (u8::MAX - 1, true));
RunCalculates the multiplication of self
and rhs
.
Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic overflow would occur. If an overflow would have occurred then the wrapped value is returned.
Examples
Basic usage:
Please note that this example is shared between integer types.
Which explains why u32
is used here.
assert_eq!(5u32.overflowing_mul(2), (10, false));
assert_eq!(1_000_000_000u32.overflowing_mul(10), (1410065408, true));
RunCalculates the divisor when self
is divided by rhs
.
Returns a tuple of the divisor along with a boolean indicating
whether an arithmetic overflow would occur. Note that for unsigned
integers overflow never occurs, so the second value is always
false
.
Panics
This function will panic if rhs
is 0.
Examples
Basic usage
assert_eq!(5u8.overflowing_div(2), (2, false));
RunCalculates the quotient of Euclidean division self.div_euclid(rhs)
.
Returns a tuple of the divisor along with a boolean indicating
whether an arithmetic overflow would occur. Note that for unsigned
integers overflow never occurs, so the second value is always
false
.
Since, for the positive integers, all common
definitions of division are equal, this
is exactly equal to self.overflowing_div(rhs)
.
Panics
This function will panic if rhs
is 0.
Examples
Basic usage
assert_eq!(5u8.overflowing_div_euclid(2), (2, false));
RunCalculates the remainder when self
is divided by rhs
.
Returns a tuple of the remainder after dividing along with a boolean
indicating whether an arithmetic overflow would occur. Note that for
unsigned integers overflow never occurs, so the second value is
always false
.
Panics
This function will panic if rhs
is 0.
Examples
Basic usage
assert_eq!(5u8.overflowing_rem(2), (1, false));
RunCalculates the remainder self.rem_euclid(rhs)
as if by Euclidean division.
Returns a tuple of the modulo after dividing along with a boolean
indicating whether an arithmetic overflow would occur. Note that for
unsigned integers overflow never occurs, so the second value is
always false
.
Since, for the positive integers, all common
definitions of division are equal, this operation
is exactly equal to self.overflowing_rem(rhs)
.
Panics
This function will panic if rhs
is 0.
Examples
Basic usage
assert_eq!(5u8.overflowing_rem_euclid(2), (1, false));
RunNegates self in an overflowing fashion.
Returns !self + 1
using wrapping operations to return the value
that represents the negation of this unsigned value. Note that for
positive unsigned values overflow always occurs, but negating 0 does
not overflow.
Examples
Basic usage
assert_eq!(0u8.overflowing_neg(), (0, false));
assert_eq!(2u8.overflowing_neg(), (-2i32 as u8, true));
RunShifts self left by rhs
bits.
Returns a tuple of the shifted version of self along with a boolean indicating whether the shift value was larger than or equal to the number of bits. If the shift value is too large, then value is masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
Examples
Basic usage
assert_eq!(0x1u8.overflowing_shl(4), (0x10, false));
assert_eq!(0x1u8.overflowing_shl(132), (0x10, true));
RunShifts self right by rhs
bits.
Returns a tuple of the shifted version of self along with a boolean indicating whether the shift value was larger than or equal to the number of bits. If the shift value is too large, then value is masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
Examples
Basic usage
assert_eq!(0x10u8.overflowing_shr(4), (0x1, false));
assert_eq!(0x10u8.overflowing_shr(132), (0x1, true));
RunCalculates the smallest value greater than or equal to self
that
is a multiple of rhs
.
Panics
This function will panic if rhs
is 0 or the operation results in overflow.
Examples
Basic usage:
#![feature(int_roundings)]
assert_eq!(16_u8.next_multiple_of(8), 16);
assert_eq!(23_u8.next_multiple_of(8), 24);
RunCalculates the smallest value greater than or equal to self
that
is a multiple of rhs
. Returns None
is rhs
is zero or the
operation would result in overflow.
Examples
Basic usage:
#![feature(int_roundings)]
assert_eq!(16_u8.checked_next_multiple_of(8), Some(16));
assert_eq!(23_u8.checked_next_multiple_of(8), Some(24));
assert_eq!(1_u8.checked_next_multiple_of(0), None);
assert_eq!(u8::MAX.checked_next_multiple_of(2), None);
RunReturns the smallest power of two greater than or equal to self
.
When return value overflows (i.e., self > (1 << (N-1))
for type
uN
), it panics in debug mode and the return value is wrapped to 0 in
release mode (the only situation in which method can return 0).
Examples
Basic usage:
assert_eq!(2u8.next_power_of_two(), 2);
assert_eq!(3u8.next_power_of_two(), 4);
RunReturns the smallest power of two greater than or equal to n
. If
the next power of two is greater than the type’s maximum value,
None
is returned, otherwise the power of two is wrapped in Some
.
Examples
Basic usage:
assert_eq!(2u8.checked_next_power_of_two(), Some(2));
assert_eq!(3u8.checked_next_power_of_two(), Some(4));
assert_eq!(u8::MAX.checked_next_power_of_two(), None);
RunReturns the smallest power of two greater than or equal to n
. If
the next power of two is greater than the type’s maximum value,
the return value is wrapped to 0
.
Examples
Basic usage:
#![feature(wrapping_next_power_of_two)]
assert_eq!(2u8.wrapping_next_power_of_two(), 2);
assert_eq!(3u8.wrapping_next_power_of_two(), 4);
assert_eq!(u8::MAX.wrapping_next_power_of_two(), 0);
RunReturn the memory representation of this integer as a byte array in native byte order.
As the target platform’s native endianness is used, portable code
should use to_be_bytes
or to_le_bytes
, as appropriate,
instead.
Examples
let bytes = 0x12u8.to_ne_bytes();
assert_eq!(
bytes,
if cfg!(target_endian = "big") {
[0x12]
} else {
[0x12]
}
);
RunCreate a native endian integer value from its representation as a byte array in big endian.
Examples
let value = u8::from_be_bytes([0x12]);
assert_eq!(value, 0x12);
RunWhen starting from a slice rather than an array, fallible conversion APIs can be used:
fn read_be_u8(input: &mut &[u8]) -> u8 {
let (int_bytes, rest) = input.split_at(std::mem::size_of::<u8>());
*input = rest;
u8::from_be_bytes(int_bytes.try_into().unwrap())
}
RunCreate a native endian integer value from its representation as a byte array in little endian.
Examples
let value = u8::from_le_bytes([0x12]);
assert_eq!(value, 0x12);
RunWhen starting from a slice rather than an array, fallible conversion APIs can be used:
fn read_le_u8(input: &mut &[u8]) -> u8 {
let (int_bytes, rest) = input.split_at(std::mem::size_of::<u8>());
*input = rest;
u8::from_le_bytes(int_bytes.try_into().unwrap())
}
RunCreate a native endian integer value from its memory representation as a byte array in native endianness.
As the target platform’s native endianness is used, portable code
likely wants to use from_be_bytes
or from_le_bytes
, as
appropriate instead.
Examples
let value = u8::from_ne_bytes(if cfg!(target_endian = "big") {
[0x12]
} else {
[0x12]
});
assert_eq!(value, 0x12);
RunWhen starting from a slice rather than an array, fallible conversion APIs can be used:
fn read_ne_u8(input: &mut &[u8]) -> u8 {
let (int_bytes, rest) = input.split_at(std::mem::size_of::<u8>());
*input = rest;
u8::from_ne_bytes(int_bytes.try_into().unwrap())
}
Run👎 Deprecating in a future Rust version: replaced by the MIN
associated constant on this type
replaced by the MIN
associated constant on this type
New code should prefer to use
u8::MIN
instead.
Returns the smallest value that can be represented by this integer type.
👎 Deprecating in a future Rust version: replaced by the MAX
associated constant on this type
replaced by the MAX
associated constant on this type
New code should prefer to use
u8::MAX
instead.
Returns the largest value that can be represented by this integer type.
Calculates the complete product self * rhs
without the possibility to overflow.
This returns the low-order (wrapping) bits and the high-order (overflow) bits of the result as two separate values, in that order.
Examples
Basic usage:
Please note that this example is shared between integer types.
Which explains why u32
is used here.
#![feature(bigint_helper_methods)]
assert_eq!(5u32.widening_mul(2), (10, 0));
assert_eq!(1_000_000_000u32.widening_mul(10), (1410065408, 2));
RunCalculates the “full multiplication” self * rhs + carry
without the possibility to overflow.
This returns the low-order (wrapping) bits and the high-order (overflow) bits of the result as two separate values, in that order.
Performs “long multiplication” which takes in an extra amount to add, and may return an additional amount of overflow. This allows for chaining together multiple multiplications to create “big integers” which represent larger values.
Examples
Basic usage:
Please note that this example is shared between integer types.
Which explains why u32
is used here.
#![feature(bigint_helper_methods)]
assert_eq!(5u32.carrying_mul(2, 0), (10, 0));
assert_eq!(5u32.carrying_mul(2, 10), (20, 0));
assert_eq!(1_000_000_000u32.carrying_mul(10, 0), (1410065408, 2));
assert_eq!(1_000_000_000u32.carrying_mul(10, 10), (1410065418, 2));
assert_eq!(u8::MAX.carrying_mul(u8::MAX, u8::MAX), (0, u8::MAX));
RunIf carry
is zero, this is similar to overflowing_mul
,
except that it gives the value of the overflow instead of just whether one happened:
#![feature(bigint_helper_methods)]
let r = u8::carrying_mul(7, 13, 0);
assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(7, 13));
let r = u8::carrying_mul(13, 42, 0);
assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(13, 42));
RunThe value of the first field in the returned tuple matches what you’d get
by combining the wrapping_mul
and
wrapping_add
methods:
#![feature(bigint_helper_methods)]
assert_eq!(
789_u16.carrying_mul(456, 123).0,
789_u16.wrapping_mul(456).wrapping_add(123),
);
RunMakes a copy of the value in its ASCII upper case equivalent.
ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.
To uppercase the value in-place, use make_ascii_uppercase
.
Examples
let lowercase_a = 97u8;
assert_eq!(65, lowercase_a.to_ascii_uppercase());
RunMakes a copy of the value in its ASCII lower case equivalent.
ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.
To lowercase the value in-place, use make_ascii_lowercase
.
Examples
let uppercase_a = 65u8;
assert_eq!(97, uppercase_a.to_ascii_lowercase());
RunConverts this value to its ASCII upper case equivalent in-place.
ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.
To return a new uppercased value without modifying the existing one, use
to_ascii_uppercase
.
Examples
let mut byte = b'a';
byte.make_ascii_uppercase();
assert_eq!(b'A', byte);
RunConverts this value to its ASCII lower case equivalent in-place.
ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.
To return a new lowercased value without modifying the existing one, use
to_ascii_lowercase
.
Examples
let mut byte = b'A';
byte.make_ascii_lowercase();
assert_eq!(b'a', byte);
RunChecks if the value is an ASCII alphabetic character:
- U+0041 ‘A’ ..= U+005A ‘Z’, or
- U+0061 ‘a’ ..= U+007A ‘z’.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';
assert!(uppercase_a.is_ascii_alphabetic());
assert!(uppercase_g.is_ascii_alphabetic());
assert!(a.is_ascii_alphabetic());
assert!(g.is_ascii_alphabetic());
assert!(!zero.is_ascii_alphabetic());
assert!(!percent.is_ascii_alphabetic());
assert!(!space.is_ascii_alphabetic());
assert!(!lf.is_ascii_alphabetic());
assert!(!esc.is_ascii_alphabetic());
RunChecks if the value is an ASCII uppercase character: U+0041 ‘A’ ..= U+005A ‘Z’.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';
assert!(uppercase_a.is_ascii_uppercase());
assert!(uppercase_g.is_ascii_uppercase());
assert!(!a.is_ascii_uppercase());
assert!(!g.is_ascii_uppercase());
assert!(!zero.is_ascii_uppercase());
assert!(!percent.is_ascii_uppercase());
assert!(!space.is_ascii_uppercase());
assert!(!lf.is_ascii_uppercase());
assert!(!esc.is_ascii_uppercase());
RunChecks if the value is an ASCII lowercase character: U+0061 ‘a’ ..= U+007A ‘z’.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';
assert!(!uppercase_a.is_ascii_lowercase());
assert!(!uppercase_g.is_ascii_lowercase());
assert!(a.is_ascii_lowercase());
assert!(g.is_ascii_lowercase());
assert!(!zero.is_ascii_lowercase());
assert!(!percent.is_ascii_lowercase());
assert!(!space.is_ascii_lowercase());
assert!(!lf.is_ascii_lowercase());
assert!(!esc.is_ascii_lowercase());
RunChecks if the value is an ASCII alphanumeric character:
- U+0041 ‘A’ ..= U+005A ‘Z’, or
- U+0061 ‘a’ ..= U+007A ‘z’, or
- U+0030 ‘0’ ..= U+0039 ‘9’.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';
assert!(uppercase_a.is_ascii_alphanumeric());
assert!(uppercase_g.is_ascii_alphanumeric());
assert!(a.is_ascii_alphanumeric());
assert!(g.is_ascii_alphanumeric());
assert!(zero.is_ascii_alphanumeric());
assert!(!percent.is_ascii_alphanumeric());
assert!(!space.is_ascii_alphanumeric());
assert!(!lf.is_ascii_alphanumeric());
assert!(!esc.is_ascii_alphanumeric());
RunChecks if the value is an ASCII decimal digit: U+0030 ‘0’ ..= U+0039 ‘9’.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';
assert!(!uppercase_a.is_ascii_digit());
assert!(!uppercase_g.is_ascii_digit());
assert!(!a.is_ascii_digit());
assert!(!g.is_ascii_digit());
assert!(zero.is_ascii_digit());
assert!(!percent.is_ascii_digit());
assert!(!space.is_ascii_digit());
assert!(!lf.is_ascii_digit());
assert!(!esc.is_ascii_digit());
RunChecks if the value is an ASCII hexadecimal digit:
- U+0030 ‘0’ ..= U+0039 ‘9’, or
- U+0041 ‘A’ ..= U+0046 ‘F’, or
- U+0061 ‘a’ ..= U+0066 ‘f’.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';
assert!(uppercase_a.is_ascii_hexdigit());
assert!(!uppercase_g.is_ascii_hexdigit());
assert!(a.is_ascii_hexdigit());
assert!(!g.is_ascii_hexdigit());
assert!(zero.is_ascii_hexdigit());
assert!(!percent.is_ascii_hexdigit());
assert!(!space.is_ascii_hexdigit());
assert!(!lf.is_ascii_hexdigit());
assert!(!esc.is_ascii_hexdigit());
RunChecks if the value is an ASCII punctuation character:
- U+0021 ..= U+002F
! " # $ % & ' ( ) * + , - . /
, or - U+003A ..= U+0040
: ; < = > ? @
, or - U+005B ..= U+0060
[ \ ] ^ _ `
, or - U+007B ..= U+007E
{ | } ~
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';
assert!(!uppercase_a.is_ascii_punctuation());
assert!(!uppercase_g.is_ascii_punctuation());
assert!(!a.is_ascii_punctuation());
assert!(!g.is_ascii_punctuation());
assert!(!zero.is_ascii_punctuation());
assert!(percent.is_ascii_punctuation());
assert!(!space.is_ascii_punctuation());
assert!(!lf.is_ascii_punctuation());
assert!(!esc.is_ascii_punctuation());
RunChecks if the value is an ASCII graphic character: U+0021 ‘!’ ..= U+007E ‘~’.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';
assert!(uppercase_a.is_ascii_graphic());
assert!(uppercase_g.is_ascii_graphic());
assert!(a.is_ascii_graphic());
assert!(g.is_ascii_graphic());
assert!(zero.is_ascii_graphic());
assert!(percent.is_ascii_graphic());
assert!(!space.is_ascii_graphic());
assert!(!lf.is_ascii_graphic());
assert!(!esc.is_ascii_graphic());
RunChecks if the value is an ASCII whitespace character: U+0020 SPACE, U+0009 HORIZONTAL TAB, U+000A LINE FEED, U+000C FORM FEED, or U+000D CARRIAGE RETURN.
Rust uses the WhatWG Infra Standard’s definition of ASCII whitespace. There are several other definitions in wide use. For instance, the POSIX locale includes U+000B VERTICAL TAB as well as all the above characters, but—from the very same specification—the default rule for “field splitting” in the Bourne shell considers only SPACE, HORIZONTAL TAB, and LINE FEED as whitespace.
If you are writing a program that will process an existing file format, check what that format’s definition of whitespace is before using this function.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';
assert!(!uppercase_a.is_ascii_whitespace());
assert!(!uppercase_g.is_ascii_whitespace());
assert!(!a.is_ascii_whitespace());
assert!(!g.is_ascii_whitespace());
assert!(!zero.is_ascii_whitespace());
assert!(!percent.is_ascii_whitespace());
assert!(space.is_ascii_whitespace());
assert!(lf.is_ascii_whitespace());
assert!(!esc.is_ascii_whitespace());
RunChecks if the value is an ASCII control character: U+0000 NUL ..= U+001F UNIT SEPARATOR, or U+007F DELETE. Note that most ASCII whitespace characters are control characters, but SPACE is not.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';
assert!(!uppercase_a.is_ascii_control());
assert!(!uppercase_g.is_ascii_control());
assert!(!a.is_ascii_control());
assert!(!g.is_ascii_control());
assert!(!zero.is_ascii_control());
assert!(!percent.is_ascii_control());
assert!(!space.is_ascii_control());
assert!(lf.is_ascii_control());
assert!(esc.is_ascii_control());
Runpub fn escape_ascii(&self) -> EscapeDefaultⓘNotable traits for EscapeDefaultimpl Iterator for EscapeDefault type Item = u8;
pub fn escape_ascii(&self) -> EscapeDefaultⓘNotable traits for EscapeDefaultimpl Iterator for EscapeDefault type Item = u8;
impl Iterator for EscapeDefault type Item = u8;
Returns an iterator that produces an escaped version of a u8
,
treating it as an ASCII character.
The behavior is identical to ascii::escape_default
.
Examples
#![feature(inherent_ascii_escape)]
assert_eq!("0", b'0'.escape_ascii().to_string());
assert_eq!("\\t", b'\t'.escape_ascii().to_string());
assert_eq!("\\r", b'\r'.escape_ascii().to_string());
assert_eq!("\\n", b'\n'.escape_ascii().to_string());
assert_eq!("\\'", b'\''.escape_ascii().to_string());
assert_eq!("\\\"", b'"'.escape_ascii().to_string());
assert_eq!("\\\\", b'\\'.escape_ascii().to_string());
assert_eq!("\\x9d", b'\x9d'.escape_ascii().to_string());
RunTrait Implementations
Performs the +=
operation. Read more
Performs the +=
operation. Read more
Performs the &=
operation. Read more
Performs the &=
operation. Read more
Performs the |=
operation. Read more
Performs the |=
operation. Read more
Performs the |=
operation. Read more
Performs the ^=
operation. Read more
Performs the ^=
operation. Read more
This operation rounds towards zero, truncating any fractional part of the exact result.
Panics
This operation will panic if other == 0
.
Performs the /=
operation. Read more
Performs the /=
operation. Read more
Maps a byte in 0x00..=0xFF to a char
whose code point has the same value, in U+0000..=U+00FF.
Unicode is designed such that this effectively decodes bytes with the character encoding that IANA calls ISO-8859-1. This encoding is compatible with ASCII.
Note that this is different from ISO/IEC 8859-1 a.k.a. ISO 8859-1 (with one less hyphen), which leaves some “blanks”, byte values that are not assigned to any character. ISO-8859-1 (the IANA one) assigns them to the C0 and C1 control codes.
Note that this is also different from Windows-1252 a.k.a. code page 1252, which is a superset ISO/IEC 8859-1 that assigns some (not all!) blanks to punctuation and various Latin characters.
To confuse things further, on the Web
ascii
, iso-8859-1
, and windows-1252
are all aliases
for a superset of Windows-1252 that fills the remaining blanks with corresponding
C0 and C1 control codes.
type Err = ParseIntError
type Err = ParseIntError
The associated error which can be returned from parsing.
Performs the *=
operation. Read more
Performs the *=
operation. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than or equal to (for self
and other
) and is used by the >=
operator. Read more
This operation satisfies n % d == n - (n / d) * d
. The
result has the same sign as the left operand.
Panics
This operation will panic if other == 0
.
Performs the %=
operation. Read more
Performs the %=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the <<=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the >>=
operation. Read more
Performs the -=
operation. Read more
Performs the -=
operation. Read more
Map char
with code point in U+0000..=U+00FF to byte in 0x00..=0xFF with same value, failing
if the code point is greater than U+00FF.
See impl From<u8> for char
for details on the encoding.